Historians of postwar American politics often identify race as a driving force in the dynamically shifting political culture. Joshua Zeitz instead places religion and ethnicity at the fore, arguing that ethnic conflict among Irish Catholics, Italian Catholics, and Jews in New York City had a decisive impact on the shape of liberal politics long before black-white racial identity politics entered the political lexicon.

Understanding ethnicity as an intersection of class, national origins, and religion, Zeitz demonstrates that the white ethnic populations of New York had significantly diverging views on authority and dissent, community and individuality, secularism and spirituality, and obligation and entitlement. New York Jews came from Eastern European traditions that valued dissent and encouraged political agitation; their Irish and Italian Catholic neighbors tended to value commitment to order, deference to authority, and allegiance to church and community. Zeitz argues that these distinctions ultimately helped fracture the liberal coalition of the Roosevelt era, as many Catholics bolted a Democratic Party increasingly focused on individual liberties, and many dissent-minded Jews moved on to the antiliberal New Left.